Former royal butler Paul Burrell has claimed that the King's cancer diagnosis will put a lot of pressure on Prince William to "step up" as he returns to official duties in the aftermath of the Princess of Wales’s abdominal surgery.
Burrell, who overcame prostate cancer in 2022, appeared on Tuesday’s Lorraine show to react to the news that Charles is receiving treatment for an undisclosed cancer.
In the wake of his diagnosis, other royal family members will be taking over public duties such as Queen Camilla, Princess Anne and Prince William, who Mr Burrell claims has "this awful responsibility coming his way".
Burrell shared: "My sons were the first to know and whilst cancer is destructive, in a way it does bring families together and reminds you of your own mortality, which I'm sure is what the King is going through.
"Poor William, at the end of the day, because he has this awful responsibility coming his way, hurtling down the track faster than he thought he would.
"I know the King will recover from this, but it shows he is in a fragile condition, and if the King can't make the meeting in Samoa later this year, and he can't go to New Zealand for the tour, then it's going to fall back on William to do his responsibilities and to step up for the King.
"So there's an awful lot of pressure on William. His father's sick, his wife's sick and his brother's gone AWOL. Thank God for Princess Anne because she's never sick and she just soldiers on."
Mr Burrell also said he believes the diagnosis will heal the rift between Harry and the King, but insisted that William and Harry’s "is a more difficult one to mend".
The Duke of Sussex has cleared his diary to fly to the UK to be with his father despite their troubled relationship, raising concerns about the seriousness of the King’s health.
Reflecting on his own experience, Mr Burrell first shared: "It brought me closer to my sons. We speak almost every day now. We went periods where we didn't speak for weeks because they're in America and I'm here, but now we make time to speak to each other.
"I think Harry getting on an airplane from Los Angeles to see his father is a very positive move. That bridge will be mended between father and son, I have no doubt about that, as it was for me.
"But the bridge between William and Harry is a more difficult one to mend, because so much has been said, so many insults have been thrown around and what's been said can't be taken back.
"It's very difficult to mend and of course, that involves Kate as well and the wider Royal Family."
Mr Burrell added that he hopes the King’s health will "bring both brothers back together" as that is what "Diana would have wanted".
He continued: "I feel for William so much because I know how sensitive he is. I know he will do his best. I still call him William, I don't call him Prince William. It's William to me.
"When I met him in the past, I've spoken openly and honestly with him and I know he's considered and measured. He's his mother's son and he wants to do the best he can for his father - and he wants to make this work between him and his brother.
"I'm hoping this illness with the King will bring both brothers back together and that is what Diana would have wanted, it would have made her happy, and it would make the circle complete again."
On Monday, Buckingham Palace confirmed the King, who only acceded to the throne 17 months ago, is undergoing outpatient treatment for cancer.
Charles was diagnosed after a "separate issue of concern was noted" and investigated while he was being treated for his benign prostate condition.